Latify is a Google Latitude client giving you fine-grained control over how your locations should be uploaded to Google Latitude and is optimized to be very battery efficient.
It puts you in the driving seat on how frequent you want your location to be updated.

Record your journeys and save them in the cloud. Upload our locations changes to Google Latitude and/or Fusion Tables.
Revisit your location history using the interactive map viewer.
Decide for yourself how frequent the phone should process your locations (ranging from every 30 seconds to every 12 hours)
Share your current location with others, or allow others to track your location changes in real-time.
Disable the realtime location syncups when roaming abroad (or when running on a low volume data connection). Your location changes
will be stored on your phoned and can be synced at a later point in time, ex: when a WIFI connection is available, avoiding unnecessary cellular costs.

All of this in a very battery-friendly way

Value-added services include :

Fine grained location polling
Background location reporting
Location history visualization
Offline mode / delayed Google Latitude / Fusion tables sync
Battery efficiency
Fusion Tables support
Live location tracking

Please be aware that continued use of GPS running in the background can dramatically decrease battery life. This is the case when your location will be updated using GPS at a high frequency (fully configurable through the location polling profiles).